I have been using DVDit 6 for a long time with no problems. Suddenly I get a black square, almost full screen over my completed render. I can see the edges of the pict. When I play the VOB file with windows media player, its fine. When I write a dvd or watch it on other software dvd players, I see black with a small edge of picture?

My media is normal PAL 720x576i @ 420. I work with QT reference files from AVID MC v 2.8 and go straight for a "play first" with no menu. The simulation shows up fine. I have not installed any new software, although I reinstalled DVDit to check.

Any ideas?